In a single sided read system laminate type optical disc, a representative of which is a laminate type optical disc (referred to hereinafter as the laminate optical disc in some cases) such as DVD (digital video disc or digital versatile disc) or the like, it has heretofore been sufficient to bond (3) a resin substrate of a polycarbonate or the like to (2) a metal-sputter substrate. However, as to the laminate optical disc required to have a higher recording density, it has become an important technique to use a sheet of disc in the form of multilayer laminate. For recording information over the multilayer, it is necessary to additionally form, in addition to a conventional reflective film layer such as the metal sputter or the like, a layer composed of gold, silicon, a silicon compound or the like having functions of a reflecting layer and a light transmittable layer as a translucent film layer. That is to say, in a recent single sided read system multilayer type laminate optical disc, a representative of which is DVD-9 or DVD-18, it has been desired that the translucent film substrate (1) as well as the polycarbonate resin substrate and the metal-sputter substrate is also sufficiently laminated and bonded.
In bonding a film of gold, silver, silicon, a silicon compound or the like, the interface is inactive as compared with other inorganic matters, so that it has heretofore been considered to be difficult to impart chemical and physical actions effective to the bonding. As a result, the present situation is that no adhesive which is sufficiently satisfactory in performance and productivity has been provided for such reasons as no sufficient bonding strength being obtained in the bonding, a primer treatment being required, and the like.
With the conventional bonding method or adhesive, there are problems in respect of productivity in the optical disc lamination such as no sufficient bonding strength being obtained particularly as to the translucent film substrate (1) among the above-mentioned three substrates, a pretreatment such as a primer or the like being required, and the like, and the solution thereof has been desired.